| 摘要 |
<p>PURPOSE:To make a converted digital value optimum by comparing a decided input voltage with the comparing reference voltage outputted from a D/A converter and outputting the comparison result and changing the comparing reference volgage even if the decided input voltage is fluctuated. CONSTITUTION:A/D converter 23 converts the reference voltage inputted to inputted terminal 22 to a digital value by a program which is made into a ROM on a basis of another reference voltage VREF 10. D/A converter 24 generates a comparing voltage by the digital value converted by this converter 23 and voltage VREF 19 and outputs this voltage to comparator 14. Then, comparator 14 compares a decided input voltage inputted to terminal 15 with the comparing reference voltage outputted from D/A converter 24 and outputs the comparison result from terminal 17. As a result, the comparing reference voltage can be changed and be adapted easily to correct the converted digital value to an optimum value by changing the reference voltage inputted to input terminal 22 even if the decided input voltage is fluctuated.</p> |
